Retrofit sensor module for a protective head top

ABSTRACT

The present disclosure includes a retrofit sensor module for use with a protective head top with a helmet and a visor. The sensor module includes a sensor housing and an attachment mechanism. The sensor housing encloses a head presence sensor to sense when the protective head top is being worn. The sensor housing also encloses a position sensor to sense the position of the visor relative to the helmet. The retrofit sensor module further comprises an attachment mechanism secured to the housing. The attachment mechanism mates with a first hinge component of a hinge assembly in the protective head top to removably install the sensor module into the protective head top, wherein the hinge assembly allows the visor to move relative to the helmet.

TECHNICAL FIELD

The present disclosure relates to the field of personal protectiveequipment and a sensor module for retrofitting personal protectiveequipment. More specifically, the present disclosure relates to aretrofit sensor module for a protective head top.

BACKGROUND

When working in areas where there is known to be, or there is apotential of there being, dusts, fumes, gases or other contaminants thatare potentially hazardous or harmful to health, it is usual for a workerto use a respirator or a clean air supply source. While a large varietyof respiratory devices are available, some commonly used devices includepowered air purifying respirators (PAPR) or a self-contained breathingapparatus (SCBA). A PAPR typically includes a blower system comprising afan powered by an electric motor for delivering a forced flow of airthrough a tube to a head top worn by a user. A PAPR typically includes adevice (i.e., turbo) that draws ambient air through a filter, forces theair through a breathing tube and into a helmet or head top to providefiltered air to a user's breathing zone, around their nose or mouth. AnSCBA provides clean air from a compressed air tank through a tube orhose to the interior of a head top worn by a user.

In many instances, it is important for the user to be confident thattheir PPE is working correctly. Additionally, safety managers at worklocations requiring the use of PPE want to be able to confirm that theiremployees are using the correct PPE, and that the PPE is being used asintended.

SUMMARY

The present invention provides a retrofit sensor module that can beadded to an existing protective head top. A retrofit sensor moduleconsistent with the present disclosure faces the challenges of beingeasy for the user to install, use and remove on a regular basis,potentially daily basis, without tools or training. These factorstherefore required an attachment mechanism that is simple for quickaccess, yet durable enough to withstand impacts (the device may not bedislodged during a head top impact or during use for any reason), andlocated such that the device can accomplish all required sensing andinformation gathering.

The retrofit sensor module can include a variety of features. In atleast one embodiment, the retrofit sensor module for use with aprotective head top including a visor and a helmet comprises a sensorhousing and an attachment mechanism. The sensor housing encloses a headpresence sensor to sense when the protective head top is being worn. Thesensor housing also encloses a position sensor to sense the position ofthe visor relative to the helmet. The retrofit sensor module furthercomprises an attachment mechanism secured to the housing. The attachmentmechanism mates with a first hinge component of a hinge assembly in theprotective head top to removably install the sensor module into theprotective head top, wherein the hinge assembly allows the visor to moverelative to the helmet.

In some instances, the sensor housing further encloses a battery.

In some instances, the sensor housing further encloses a temperaturesensor to sense ambient temperature in the interior of the protectivehead top.

In some instances, the sensor housing further encloses an accelerometerto sense movement of the head of an individual wearing the head top.

In some instances, the sensor housing further encloses an audiotransducer.

In some instances, the user interface comprises at least one lightemitting diode (LED).

In some instances, the attachment mechanism replaces a second hingecomponent of the hinge assembly.

In some instances, the sensor module does not replace any components ofthe hinge assembly when installed in the protective head top.

In some instances, the sensor module can be installed without using anytools.

In some instances, the sensor module fits in the interior of the visorof the protective head top when the sensor module is installed in theprotective head top and when the visor is in a down position.

In some instances, the sensor module does not impair the performance ofthe hinge assembly when it is installed in the protective head top.

In some instances, the attachment mechanism is removably secured to thesensor housing.

In some instances, the attachment mechanism is an integral part of orpermanently secured to the sensor housing.

In some instances, the battery can be replaced without the use of anytools while the sensor module is installed in the protective head top.

In some instances, the sensor module has an Ingress Protection (IP)rating.

In some instances, the sensor housing further comprises a Bluetoothcommunication component.

The sensor module of claim 1, wherein the head presence sensor comprisesan infrared sensor.

The present disclosure further includes a kit comprising the sensormodule as described herein and a personal communication hub, wherein thesensor module communicates with the personal communication hub usingBluetooth.

The present disclosure further includes a kit comprising the sensormodule as described herein and the protective head top.

The present disclosure provides many advantages over the prior art. Forexample, the retrofit sensor module can allow users or owners ofprotective head tops to efficiently upgrade their head top to detectwhen the head top visor is open. Further, in some instances, theretrofit sensor module can be installed in the head top without the useof tools.

The present disclosure provides a way to confirm that a user is wearinga protective head top in some instances through the head detectionsensor. This information allows managers of safety programs to confirmthat users of protective head tops are complying with requirements towear the protective head tops.

The present disclosure provides the ability to determine whattemperature the worker is exposed to within the interior of the headtop. This allows for the determination that a worker may be overly hot,that the worker may be experiencing fatigue due to temperature, or eventhat a blower connected to the head top is not working properly.

The present disclosure provides a way to retrospectively determinewhether a visor for a protective head top was in an open position or ina closed position at the time of an event or injury.

The present disclosure can provide a solution that is durable in a workenvironment based on an Ingress Protection (IP rating).

BRIEF DESCRIPTION OF DRAWINGS

The invention may be more completely understood in consideration of thefollowing detailed description of various embodiments of the inventionin connection with the accompanying drawings, in which:

FIG. 1 is a system diagram of a protective head top, a blower and acommunication hub.

FIG. 2 a perspective view of a retrofit sensor module.

FIG. 3 is a system diagram of the electronic components in a retrofitsensor module.

FIGS. 4a and 4b are exploded views of a retrofit sensor module.

FIG. 5 is a first side of a retrofit sensor module.

FIG. 6 is a second side of a retrofit sensor module.

FIG. 7a is an enlarged view of a hinge assembly in a protective headtop.

FIG. 7b is an exemplary hinge assembly for a protective head top.

FIG. 8 shows a retrofit sensor module mated to hinge assemblycomponents.

FIGS. 9a and 9b shows a feature on the retrofit sensor module thatmatches a feature on the rear side of the pivot socket cam.

FIGS. 10a-10c show the retrofit sensor module installed in a protectivehead top.

FIG. 11 shows a retrofit sensor module superimposed onto itsinstallation location in a protective head top.

FIG. 12 shows an alternate embodiment for a retrofit sensor module.

It is to be understood that the embodiments may be utilized andstructural changes may be made without departing from the scope of theinvention. The figures are not necessarily to scale. Like numbers usedin the figures refer to like components. However, it will be understoodthat the use of a number to refer to a component in a given figure isnot intended to limit the component in another figure labeled with thesame number.

DETAILED DESCRIPTION

FIG. 1 is a system 100 diagram of a protective head top 110, a blower120 and a communication hub 130. Communication hub 130 can communicatewith communication modules in blower 120 or in a retrofit sensor module,with beacons or other sensors that may be located in the environment,and with a cloud network 140, which can provide information to a usercomputing device 150, such as a mobile device, tablet or computer.Protective head top 110 includes a visor 112 that is sized to fit overat least a user's nose and mouth. Visor 112 includes lens 116 which issecured to helmet 118 by the frame assembly 114. Hinge assemblies 113connect frame assembly 114 to helmet 118 on each side of frame assembly114. Hinge assemblies 113 allow visor 116 to rotate to an open or closedposition relative to helmet 118. Helmet 118 may also be referred to as ashell, and the terms are used interchangeably herein.

As described herein, a retrofit sensor module can be installed into theprotective head top such that an attachment mechanism of the retrofitsensor module mates with a component of hinge 113. In some instances theretrofit sensor module may replace a component of hinge 113. Retrofitsensor module may include a variety of sensors and other components,such as a position sensor. When retrofit sensor module is installed inhead top 110, the position sensor senses the position of visor 112relative to helmet 118 to determine if the visor is in an open positionor in a closed position. In some instances, a position sensor may detectwhether visor 112 is partially open, and if so, what measure (e.g.,percent or degree) it is open.

Head top 110 is connected to blower 120 by hose 119. Blower 120 can beany type of air supply source, such as a blower assembly for a poweredair purifying respirator (PAPR), an air tank for a self-containedbreathing apparatus (SCBA) or any other device that provides air to headtop 110. In FIG. 1, blower 120 is a blower assembly for a PAPR. A PAPRis commonly used by individuals working in areas where there is known tobe, or there is a potential of there being dusts, fumes or gases thatare potentially harmful or hazardous to health. A PAPR typicallyincludes blower assembly, including a fan driven by an electric motorfor delivering a forced flow of air to the respirator user. The air ispassed from the PAPR blower assembly through hose 119 to the interior ofhead top 110.

Head top 110, and specifically the helmet 118 of head top 110 may besupported on a user's head by a suspension (not shown).

A retrofit sensor module may include a communication module that allowsthe retrofit sensor to communicate information with communication hub130. Communication hub 130 includes a processor, a communication moduleand a power supply. The communication module of communication hub 130 orof a retrofit sensor module can include any desired communicationcapability, such as: RFID (including NFC), Bluetooth, including anygenerations of Bluetooth technology, and WiFi communicationcapabilities. Communication module of communication hub 130 or of aretrofit sensor module can also include any type of wirelesscommunication capabilities, such as radio frequency or Zigbeecommunication.

Communication hub 130 may include a user interface, such as a display,lights, buttons, keys (such as arrow or other indicator keys), and maybe able to provide alerts to the user in a variety of ways, such as byaudibly or visibly generating an alarm or vibrating. In some instances,the user interface of communication hub 130 may be used to controlelectronic settings for the head top 110 or the blower 120 to allow auser easier access to setting changes, particularly when the blower 120is worn in a location on the lower back where it can be difficult forthe user to reach.

Communication hub 130 can be portable such that it can be carried orworn by a user. Communication hub 130 can also be personal, such that itis used by an individual and communicates with personal protectiveequipment (PPE) assigned to that individual. In FIG. 1, communicationhub 130 is secured to a user using a strap 134. However, communicationhub may be carried by a user or secured to a user in other ways, such asbeing secured to PPE being worn by the user, to other garments beingworn to a user, being attached to a belt, band, buckle, clip or otherattachment mechanism as will be apparent to one of skill in the art uponreading the present disclosure.

Communication hub 130 can receive information from and communicateinformation to head top 110 and blower 120. Communication hub 130 sendsinformation to and receives information from a cloud database 140. Suchinformation may include status information about head top 110 and blower120, information about the movement, temperature, or other pieces ofdata related to the individual wearing head top 110 and blower 120, andinformation from other sensors or beacons that may be located in theenvironment or in communication proximity of head top 110 and blower120.

A user can access, view and modify information stored in cloud database140 through a web interface on user computing device 150, such as apersonal computer, mobile device or tablet.

FIG. 2 a perspective view of a retrofit sensor module 200. Retrofitsensor module includes a pivot socket cam 210 (opposite boss 270). Pivotsocket cam 210 and boss 270 serve as attachment mechanisms to allowretrofit sensor module 200 to be retained in a protective head top wheninstalled in the protective head top. Pivot socket cam 210 and boss 270also reproduce the cam action of a component of a hinge assembly toallow the visor to rotate or pivot relative to a helmet in a protectivehead top in the same manner after a retrofit sensor module 200 isinstalled as before it was installed.

Retrofit sensor module 200 can have a housing comprised of two sides,housing side 220 and housing side 240. These two portions of the housing(housing side 220 and housing side 240) allow the pieces of housing tobe separately molded and later sealed together after a populated printedcircuit board is installed in the housing. Multiple portions of ahousing can be permanently joined through processes such as use ofadhesive, laser welding, ultrasonic welding or any other method ofjoining or securing components to each other. The housing may also bemanufactured through a 3D-printing process. Slotted coin slot cover 260covers the opening where a small battery, such as a coin cell lithiumion battery can be inserted into the interior of the housing of retrofitsensor module 200. The battery can provide power to the electroniccomponents within retrofit sensor module 200. Slotted coin cell cover260 can be sealed to housing side 220 by an O-ring or another gasketingmethod to prevent moisture or dust entering the interior of the housing.Slotted coin cell cover 260 includes slot 262 which provides a user away to rotate and open the slotted coin cell cover 260 relative tohousing side 220 using a coin-shaped battery (such as the battery to beenclosed in the housing or recently removed from the housing) or similarcoin-shaped object.

FIG. 3 is a system diagram of the electronic components in a retrofitsensor module 310. FIG. 3 also shows how retrofit sensor module 310 mayelectronically interface with other components in a safety system.Retrofit sensor module 310 includes position sensor 311, head presencesensor 312, accelerometer 313, temperature sensor 314, communicationmodule 315 and audio transducer 316. Position sensor 311 detects theposition of the visor relative to the helmet of the protective head top.In some instances, position sensor 311 may detect whether visor 112 ispartially open, and if so, what measure (e.g., percent or degree) it isopen. As an example, the position sensor 311 may be a gyroscope thatcomputes angular yaw, pitch, and/or roll (in degrees or radians) of thevisor relative to the helmet. In another example, the position sensor311 may be a magnetometer that measures the change relative to a magnetinstalled in a component of the hinge assembly. A percent may beestimated respecting how open a visor is in relation to the helmet bydetermining the magnetic field strength or flux perceived by theposition sensor 311. “Partially open” visor information can be used todenote that the user may be receiving eye and face protection forhazards while still receiving a reasonable amount of respiratoryprotection. This “partially open” visor state, if kept to shortdurations, can assist the user in face to face communications with otherworkers. Position sensor 111 can be a variety of types of sensors, forexample, an accelerometer, gyro, magnet, switch, potentiometer, digitalposition sensor or air pressure sensor. Position sensor 111 can also bea combination of any of the sensors listed above, or any other types ofsensors that can be used to detected the position of the visor relativeto the helmet.

Head presence sensor 312 can detect whether the protective head top isbeing worn by a user at any given point in time. In one instance, headpresence sensor 312 may be an infrared sensor. The location of theretrofit sensor module when installed in a protective head top near thesuspension that supports the head top on a user's head allows aninfrared sensor to be positioned to detect whether a user is wearing theprotective head top. Other types of sensors that may be used to detectwhether an individual is wearing the protective head top include acapacitive sensor, a reed switch, carbon dioxide sensor, passive opticalsensor, thermal sensor or an electro-mechanical switch.

Accelerometer 313 can detect the movement of a user's head when theprotective head top is being worn. Such motion detection can allow foridentification of activity that may injure the worker. Additionally, ifthe protective head top with a retrofit sensor module is not worn, nomotion will be detected by accelerometer 313, allowing the accelerometer313 to be used to confirm when the head top is not being worn.Accelerometer 313 can be used to detect occurrence of an impact or ahigh acceleration fall to determine additional detail when dangerousevents occur.

Temperature sensor 314 senses the ambient temperature in the interior ofa protective head top when retrofit sensor module 310 is installed in aprotective head top. Temperature sensor 314 may be used to gatherinformation such as whether the visor is open in a high temperatureenvironment, whether the individual wearing the protective head top isbeing exposed to a high degree of heat and whether the blower 320 is notcirculated air within the interior of the protective head top.

Audio transducer 316 can analyze the noise level in an environment, suchas the interior of the protective head top or the area just external tothe protective head top and near the user's ear, especially in theabsence of a user wearing hearing protection, to determine if anenvironment is safe or dangerous to a user's hearing. In someembodiments, audio transducer 316 may be located in a portion of thehousing of the retrofit sensor module that is situated near a user's earand exposed to an exterior environment to allow sensing of environmentalnoise levels and exposure. In some instances, audio transducer 316 maydetermine the origination location or direction of noise and alert theuser to approaching objects or people.

Communications module 315 allows retrofit sensor module to communicatewith other electronic devices, such as communication hub 330. Acommunication module may include a variety of communicationcapabilities, such as radio frequency identification (RFID) (includingNFC), Bluetooth, including any generations of Bluetooth, such asBluetooth low energy (BLE), any type of wireless communication, such asWiFi, Zigbee, radio frequency or other types of communication methods aswill be apparent to one of skill in the art up one reading the presentdisclosure. Communication module 315 can electronically interface withsensors, such as position sensor 311, head presence sensor 312,temperature sensor 313, accelerometer 314 or audio transducer 316 suchthat it can transmit information from these sensors to other electronicdevices, including communication hub 330.

Retrofit sensor module 310 may include other types of sensors orelectronic components, such as a verbal communication module, a powersource such as a battery and a processing component, a USB or otherconnection for recharging batteries or removing information and otherelectro-mechanical connections.

Communication hub 330 includes a processor 331, a communication module332 and a power supply (not shown). The communication module 332 ofcommunication hub 330 can include any desired communication capability,such as: RFID, Bluetooth, including any generations of Bluetoothtechnology, and WiFi communication capabilities. Communication hub 130can also include any type of wireless communication capabilities, suchas radio frequency or Zigbee communication.

Communication hub 330 power supply can provide power to both theprocessor and communication module. A rechargeable battery, such as aLithium Ion battery, can provide a compact and long-life source ofpower. Communication hub 330 may be adapted to have electrical contactsexposed or accessible from the exterior of the hub to allow rechargingthe communication hub 330.

Communication hub 130 processor 331 can receive, store and processinformation. For example, communication module 332 in communication hub330 may receive information from a communication module 315 in retrofitsensor module 310 or directly from the position sensor 311 indicatingthe position of the visor, whether the visor is open or closed, and atwhat time the visor position changed. Processor 331 in communication hub330 can store this information and compare it with other informationreceived. Other information received may include, for example,information from a user's computing device 350 environmental beacon orsensor (not shown) and information from cloud database 340.Communication hub 330 can further store rules, such as thresholdinformation both for a length of time the visor is allowed to be in anopen position before an alert is generated, and the level or type ofcontaminants that will trigger an alert. For example, when communicationhub 330 receives information from an environmental beacon or sensorindicating that there are no known hazards in the environment, thethreshold for the visor being in the open position may be infinite. If ahazard is present in the environment, then the threshold would bedetermined based upon the concern of the threat to the user. Radiation,dangerous gases, or toxic fumes would all require assignment of thethreshold to be on the order of one second or less.

Thresholds for other variables, such as for head top interiortemperature can be used to predict heat related illness and morefrequent hydration and/or rest periods can be recommended to the user.Thresholds can be used to alert a user of a remaining amount ofpredicted battery run time. As the battery nears its remaining run time,the user can be notified/warned to complete their current task and seeka fresh battery. When a threshold is exceeded for a specificenvironmental hazard, an urgent alert can be given to the user toevacuate the immediate area.

Thresholds can be adjusted and individualized for a user based onfactors such as the user's age, gender, or state of health. Thresholdsrelated to remaining battery life can be adjusted based on anticipatedtime to don and doff PPE.

Blower 320 includes a motor and fan assembly that provides a pressurizedsource of air to the head top. Additionally, blower 320 includes aprocessor 324 and a communication module 322. Processor 324 mayinterface with other components within blower 320. For example,processor 324 may interface with the battery or power source for blower320 to determine how much battery life remains for the particularbattery at any given point in time. Processor 324 may also communicatewith the motor controlling fan speed, to determine how much air is beingforced through the filter in blower 320, and therefore estimateremaining filter life. Communication module 322 is in electricalcommunication with processor 324. Communication module 322 may includeany desired communication capability, such as: RFID (including NFC),Bluetooth, including any generations of Bluetooth technology, and WiFicommunication capabilities. Communication module 322 can also includeany type of wireless communication capabilities, such as radio frequencyor Zigbee communication. Communication module can communicate wirelesslywith communication hub 330. In some instances, communication module maycommunicate with other devices, such as cloud database 340 and usercomputing device 350, such as a personal computer, mobile device ortablet.

FIGS. 4a and 4b are exploded views of a retrofit sensor module 400,showing each a perspective view of one side of the components inretrofit sensor module 400. Pivot socket cam 410 may be manufactured asa single component and later attached to retrofit sensor module housing420, or may be manufactured as a continuous component with retrofitsensor module housing 420. In some configurations, pivot socket cam 410serves as an attachment mechanism to attach retrofit sensor module 400to the protective head top. Pivot socket cam 410 may be removablysecured to the sensor housing 420. Pivot socket cam 410 may be anintegral part of or permanently secured to the retrofit sensor modulehousing.

Pivot socket cam 410 has two sides, shown in FIGS. 4a and 4b ,respectively. Pivot socket cam 410, in the embodiment shown, replaces acomponent of the hinge assembly in a protective head top. Specifically,the side of pivot socket cam 410 shown in FIG. 4b makes visible thedetents that mate with a socket cam of the protective head top hingeassembly. In some configurations, pivot socket cam 410 may optionallyinclude an annular (or other) retaining feature, sometimes also referredto as a boss, on the same side as the detents to increase security andbetter retain the retrofit sensor module in its installed location inthe protective head top. In some other embodiments, the sensor moduledoes not replace any components of the hinge when installed in theprotective head top. One advantage of the present invention is that theinstallation of the sensor module does not impair the performance of thehinge when it is installed in the protective head top.

The side of pivot socket cam shown in FIG. 4a includes a small boss thatseats into a molded pocket within the helmet. Bosses may be any shape,such as a square, trapezoid, or any shape used to mate to existingfeatures of a protective helmet or components of a hinge assembly. Thefeature provides a mechanical interference that further prevents theretrofit sensor module from inadvertently being dislodged from theprotective head top, especially in the instance the wearer of the helmetexperiences a top impact while wearing the helmet.

Retrofit sensor module housing side 420 includes several ribs (visiblein FIG. 4a ) adding stability to the housing, slightly spacing the backside of printed circuit board 430 from the interior surface of retrofithousing side 420 to allow cooling of the components mounted on the PCB.

Printed circuit board (PCB) 430 hosts the electronic components inretrofit sensor module 400. While other methods of integratingelectronic packages into devices will be apparent to one of skill in theart upon reading the present disclosure, use of a PCB to mount andconnect components is shown in this embodiment. PCB may host a varietyof components, including sensors, communication modules, processors andother components. PCB has mounted on it a set of springs to create anelectrical contact with coin cell battery 435. Coin cell battery 435 isnot secured to the PCB in the embodiment shown in FIGS. 4a and 4b , butrather in contact with it. This allows coin cell battery 435 to bereplaced. In some embodiments, coin cell battery 435 can be replacedwithout tools when retrofit sensor module is installed in a protectivehead top.

Retrofit sensor module housing side 440 can be manufactured through amolding process and permanently attached to retrofit sensor modulehousing 420 using processes such as adhesives and ultrasonic welding.Retrofit sensor housing module side 440 includes opening 443 by which acoin cell battery 435 can be accessed and replaced. Retrofit sensorhousing module side 440 includes lip 442, which provides a restinglocation for O-ring 450. O-ring 450 provides a tight seal betweenretrofit sensor housing module 442 and slotted coin slot cover 460. Thistight seal, along with other manufacturing and design choices allows theretrofit sensor module to achieve various ingress protection (IP)ratings defined by the IEC 60529 standard, managed by the AmericanNational Standards Institute (ANSI). For example, in one embodiment, theretrofit sensor module may have an IP rating of 67, indicative of itsrespective solid protection and liquid protection ratings. Lower orhigher ratings may be used depending on the likely environment for usefor the retrofit sensor module and the protective head top it isinstalled in.

FIG. 5 is a first side of a retrofit sensor module 500. This view ofretrofit sensor module 500 shows a retrofit sensor module housing side520 and pivot socket cam 510. Pivot socket cam 510 includes detents thatmate with a socket cam of the protective head top hinge assembly.

FIG. 6 is a second side of a retrofit sensor module 600. This view ofretrofit sensor module 600 shows a retrofit sensor module housing side640, the back side of pivot socket cam 610, which includes boss 616,slotted coin cell cover 660 that fits into coin cell opening 642.Slotted coin cell cover includes slot 662 which allows coin cell coverto be removed from retrofit sensor module housing side 640 with only theuse of a coin cell battery or other coin-shaped object or a fingernailand no other tools.

FIG. 7a is an enlarged view of a hinge assembly 710 in a protective headtop 700. FIG. 7b is an exemplary hinge assembly for a protective headtop.

While any number of protective head tops could be used consistent withthe scope of the present disclosure, some exemplary head tops includethe 3M M-Series Headgear Family, available for purchase from 3M Companyof St. Paul, Minn. This family of headgear includes the M-100 SeriesFaceshields, the M-300 Series Hardhats and the M-400 Series Helmets.

Hinge assembly 710 includes three main components: socket cam 712,spring clip 714 and pivot socket cam 716. The hinge assembly 710functions in a manner such that as the visor 720 of the protective headtop 700 is opened, the socket cam 712 rotates with the visor and unseatsfrom the detents within the pivot socket cam 716. Once the male featuresof the socket cam 712 find the next series of detents in the pivotsocket cam 716, the visor snaps into that position. The spring clip 714provides the force to hold the socket cam features within the pivotsocket cam 716 detents.

Hinge assembly 710 can be removed from protective head top 700 by firstremoving spring clip 714. Spring clip 714 can be removed by squeezingthe edge of the spring clip 714 toward the pivot socket cam 716 andpulling the spring clip out from the opening 730 in the rim of theprotective head top. After the spring clip 714 is removed, visor 720 andframe assembly along with socket cam 712 can be pulled away from theopening in the side of protective head top. Pivot socket cam 716 canthen be slid out of opening 730 in the rim of protective head top.

FIG. 8 shows a retrofit sensor module 800 mated to a hinge assemblycomponent. Specifically, retrofit sensor module 800 includes attachmentmechanism 816, which serves as a replacement for pivot socket cam 716 inhinge assembly 810. Attachment 816 can replicate the pivot socket camfeatures as shown in FIG. 4 b.

FIGS. 9a and 9b show a boss feature 906 on the retrofit sensor module900 that matches a boss feature 916 on the rear side of the pivot socketcam 912. The boss feature on each of retrofit sensor module 900 andsocked cam pivot 912 seats into a molded pocket within the helmet shelland provides a mechanical interference that further prevents the partfrom being dislodged from the helmet.

FIGS. 10a-10c show the retrofit sensor module 1100 installed in aprotective head top 1000. FIGS. 10a and 10b show front and side viewsrespectively of retrofit sensor module 1100 and protective head top1000. As can be seen from FIG. 10b , when retrofit sensor module isinstalled in protective head top 1000, the sensor module fits in theinterior of the visor when the visor is in a down position.

Retrofit sensor module 1100 can be installed in protective head top 1000without the use of any tools. To install retrofit sensor module 1100,the hinge assembly must first be removed as discussed with respect toFIGS. 7a and 7b . After the hinge assembly is removed, the attachmentmechanism portion of the retrofit sensor module 1100 can be insertedinto the opening in the frame of the protective head top where the pivotsocket cam once was. After the retrofit sensor module 1100 is inposition, the socket cam 1112 can be reinserted through the opening inthe frame of the protective head top to mate with the attachmentmechanism portion of the retrofit sensor module 1100 that imitates thatpivot socket cam. The spring clip 1114 can then be reinserted to createforce between the retrofit sensor module 1100 and the socket cam.

In some instances, where the position sensor in the retrofit sensormodule is a magnetometer, a magnet may be inserted into, attached to, orotherwise incorporated into the socket cam. This allows the magnetometerto detect the motion of the visor relative retrofit sensor modulebecause the motion socket cam of the socket cam relative to the retrofitsensor module is the same as or comparable to the motion of the visorrelative to the helmet of the protective head top.

Other configurations for use of a magnetometer or a magnet used forsensing the position of the visor are included in the scope of thepresent disclosure. The magnet may be physically installed in a varietyof was as will be apparent to one of skill in the art upon reading thepresent disclosure. Other locations and methods of magnet attachmentwill be apparent to one of skill in the art upon reading the presentdisclosure.

In some instances, the retrofit sensor module can be sold as a kit alongwith a communication hub. The retrofit sensor module may be designed tocommunicate with the sensor hub via Bluetooth. In some instances, theretrofit sensor module be require minimal or no calibration by the user.In some instances, that kit may further include a replacement socket camthat includes a magnet for purposes of allowing a magnetometer in theretrofit sensor module to detect the position of the visor relative tothe helmet. In some instances, the kit may further include a protectivehead top.

FIG. 11 shows a retrofit sensor module 1110 superimposed onto itsinstallation location in a protective head top 1100.

FIG. 12 shows an alternate embodiment for a retrofit sensor module 1200.In the illustrated embodiment, the retrofit sensor module includes clip1215 to serve as an attachment mechanism, to attach the retrofit sensormodule to the socket cam or to another component of a hinge assembly.Clip 1215 is designed so that its legs snap around the cam socket andits feet seat into the pivot sockets.

Many other embodiments and methods for attaching retrofit sensor moduleto a hinge assembly of a protective head top will be apparent to one ofskill in the art upon reading the present disclosure.

Other variations on the retrofit sensor module are also within the scopeof this disclosure. For example, in some instances the sensor moduleincludes a user interface, and the user interface comprises at least oneLED. A user interface may include other features that allow it tocommunicate with the user, such as a power button or switch, a speakerto transmit audio messages, a vibration ability for the purpose ofalarming, a display or a light.

It will be appreciated that numerous and varied other arrangements maybe readily devised by those skilled in the art without departing fromthe spirit and scope of the invention as claimed.

It will be appreciated that based on the above description, aspects ofthe disclosure include methods and systems for determining time of use(wear time) of articles, such as PPE articles, by determining if theysatisfy at least one criterion.

Although the methods and systems of the present disclosure have beendescribed with reference to specific exemplary embodiments, those ofordinary skill in the art will readily appreciate that changes andmodifications may be made thereto without departing from the spirit andscope of the present disclosure.

In the present detailed description of the preferred embodiments,reference is made to the accompanying drawings, which illustratespecific embodiments in which the invention may be practiced. Theillustrated embodiments are not intended to be exhaustive of allembodiments according to the invention. It is to be understood thatother embodiments may be utilized and structural or logical changes maybe made without departing from the scope of the present invention. Thefollowing detailed description, therefore, is not to be taken in alimiting sense, and the scope of the present invention is defined by theappended claims.

Unless otherwise indicated, all numbers expressing feature sizes,amounts, and physical properties used in the specification and claimsare to be understood as being modified in all instances by the term“about.” Accordingly, unless indicated to the contrary, the numericalparameters set forth in the foregoing specification and attached claimsare approximations that can vary depending upon the desired propertiessought to be obtained by those skilled in the art utilizing theteachings disclosed herein.

As used in this specification and the appended claims, the singularforms “a,” “an,” and “the” encompass embodiments having pluralreferents, unless the content clearly dictates otherwise. As used inthis specification and the appended claims, the term “or” is generallyemployed in its sense including “and/or” unless the content clearlydictates otherwise.

Spatially related terms, including but not limited to, “proximate,”“distal,” “lower,” “upper,” “beneath,” “below,” “above,” and “on top,”if used herein, are utilized for ease of description to describe spatialrelationships of an element(s) to another. Such spatially related termsencompass different orientations of the device in use or operation inaddition to the particular orientations depicted in the figures anddescribed herein. For example, if an object depicted in the figures isturned over or flipped over, portions previously described as below orbeneath other elements would then be above or on top of those otherelements.

As used herein, when an element, component, or layer for example isdescribed as forming a “coincident interface” with, or being “on,”“connected to,” “coupled with,” “stacked on” or “in contact with”another element, component, or layer, it can be directly on, directlyconnected to, directly coupled with, directly stacked on, in directcontact with, or intervening elements, components or layers may be on,connected, coupled or in contact with the particular element, component,or layer, for example. When an element, component, or layer for exampleis referred to as being “directly on,” “directly connected to,”“directly coupled with,” or “directly in contact with” another element,there are no intervening elements, components or layers for example. Thetechniques of this disclosure may be implemented in a wide variety ofcomputer devices, such as servers, laptop computers, desktop computers,notebook computers, tablet computers, hand-held computers, smart phones,and the like. Any components, modules or units have been described toemphasize functional aspects and do not necessarily require realizationby different hardware units. The techniques described herein may also beimplemented in hardware, software, firmware, or any combination thereof.Any features described as modules, units or components may beimplemented together in an integrated logic device or separately asdiscrete but interoperable logic devices. In some cases, variousfeatures may be implemented as an integrated circuit device, such as anintegrated circuit chip or chipset. Additionally, although a number ofdistinct modules have been described throughout this description, manyof which perform unique functions, all the functions of all of themodules may be combined into a single module, or even split into furtheradditional modules. The modules described herein are only exemplary andhave been described as such for better ease of understanding.

If implemented in software, the techniques may be realized at least inpart by a computer-readable medium comprising instructions that, whenexecuted in a processor, performs one or more of the methods describedabove. The computer-readable medium may comprise a tangiblecomputer-readable storage medium and may form part of a computer programproduct, which may include packaging materials. The computer-readablestorage medium may comprise random access memory (RAM) such assynchronous dynamic random access memory (SDRAM), read-only memory(ROM), non-volatile random access memory (NVRAM), electrically erasableprogrammable read-only memory (EEPROM), FLASH memory, magnetic oroptical data storage media, and the like. The computer-readable storagemedium may also comprise a non-volatile storage device, such as ahard-disk, magnetic tape, a compact disk (CD), digital versatile disk(DVD), Blu-ray disk, holographic data storage media, or othernon-volatile storage device.

The term “processor,” as used herein may refer to any of the foregoingstructure or any other structure suitable for implementation of thetechniques described herein. In addition, in some aspects, thefunctionality described herein may be provided within dedicated softwaremodules or hardware modules configured for performing the techniques ofthis disclosure. Even if implemented in software, the techniques may usehardware such as a processor to execute the software, and a memory tostore the software. In any such cases, the computers described hereinmay define a specific machine that is capable of executing the specificfunctions described herein. Also, the techniques could be fullyimplemented in one or more circuits or logic elements, which could alsobe considered a processor.

What is claimed is:
 1. A retrofit sensor module for use with aprotective head top with a helmet and a visor, the sensor modulecomprising: a sensor housing, the sensor housing enclosing: a headpresence sensor to sense when the protective head top is being worn; anda position sensor to sense the position of the visor relative to thehelmet; an attachment mechanism secured to the housing, wherein theattachment mechanism mates with a first hinge component of a hingeassembly in the protective head top to removably install the sensormodule into the protective head top, wherein the hinge assembly allowsthe visor to move relative to the helmet.
 2. The sensor module of claim1, wherein the sensor housing further encloses a battery.
 3. The sensormodule of claim 1, wherein the sensor housing further encloses atemperature sensor to sense ambient temperature in the interior of theprotective head top.
 4. The sensor module of claim 1, wherein the sensorhousing further encloses an accelerometer to sense movement of the headof an individual wearing the head top.
 5. The sensor module of claim 1,wherein the sensor housing further encloses an audio transducer.
 6. Thesensor module of claim 1, further comprising a user interface, whereinthe user interface comprises at least one LED.
 7. The sensor module ofclaim 1, wherein the hinge assembly further includes a second hingecomponent and the attachment mechanism replaces the second hingecomponent.
 8. The sensor module of claim 1, wherein the sensor moduledoes not replace any components of the hinge assembly when installed inthe protective head top.
 9. The sensor module of claim 1, wherein thesensor module can be installed without using any tools.
 10. The sensormodule of claim 1, wherein the sensor module fits in the interior of thevisor of the protective head top when the sensor module is installed inthe protective head top and when the visor is in a down position. 11.The sensor module of claim 1, wherein the sensor module does not impairthe performance of the hinge assembly when it is installed in theprotective head top.
 12. The sensor module of claim 1, wherein theattachment mechanism is removably secured to the sensor housing.
 13. Thesensor module of claim 1, wherein the attachment mechanism is anintegral part of or permanently secured to the sensor housing.
 14. Thesensor module of claim 1, wherein the battery can be replaced withoutthe use of any tools while the sensor module is installed in theprotective head top.
 15. The sensor module of claim 1, wherein thesensor module has an Ingress Protection (IP) rating.
 16. The sensormodule of claim 1, wherein the sensor housing further comprises aBluetooth communication component.
 17. The sensor module of claim 1,wherein the head presence sensor comprises an infrared sensor.
 18. A kitcomprising the sensor module of claim 16 and a personal communicationhub, wherein the sensor module communicates with the personalcommunication hub using Bluetooth.
 19. A kit comprising the sensormodule of claim 1 and the protective head top.